Hi, any ideas on what to do about hail damage to the gel coat? I know nothing about gel coat repair, is it possible to do yourself, or am I looking at having the whole boat done somewhere? Maybe I can talk the insurance adjuster into new Maarstrom hulls?! Any info would be appreciated (see pics for damage) Al
You can do a gel coat repair, but if the fiberglass is damaged as well you should sand the damaged areas. Then fill them with thickened epoxy. Sand well afterwards before painting/spray painting the area with several layers of paint.
I have never done a gel coat repair, but I have done several repairs on my '94 Marstrøm in this way.
the easiest way to fix this, if you're just worried about stopping a leak quick, is to drill out that section, and fill it in with a marine-tex material. Don't drill through both layers of glass, just through the foam.
Parts and procedure for gel coat repair that I did myself are below. We had two repair areas, one on the bow and one half-dollar size on the side of the hull, before pictures attached.
Basic Parts: Gel coat, got it from the manufacture, West Marine stocks other gel coats, may have been close enough Hardener, just bought all purpose hardener from Home Depot Two Preval Sprayer, bought at Home Depot Form Release, Marine stores have small bottle of this stuff, Home Depot didn't have it when I was looking. Blue Masking tape, bought Home Depot Paper or plastic, did not use be will next time to protect more area from over spray Acetone, bought Home Depot Rags Wet sand Sandpaper, I used 1000 and 1200, Next time will start with 800 and work up. Sandpaper, 350 - 400, something like that to rough up application surface Glove and eye protection would be good idea.
Basic Procedure, as I recall it: Choose the proper day. Gel coat with added hardener has a working range, different number of drops of hardener needed for different temperatures. If its windy, pick another day, you don't want to have to wet sand someone else's boat because your spray traveled with the wind.
Prepare surface with 350 - 400 sandpaper, be careful not to create more work by doing to much with this grit paper, less is probably better. Directions for epoxy repair say to feather out the repair on a 12:1 slope. I followed this direction for the gel coat also.
Wipe away dust, use acetone to thoroughly clean.
Mask off area of repair, including feathered area. Use paper or plastic and tape to protect against over spray.
Put in an ounce or two of gel coat into the spray bottle, use acetone as a thinner. I used about 10%, rough estimate, I have been told I should have used 50% acetone, it would have sprayed better. I will try 50% next time. Add appropriate drops of hardener for weather conditions. Mix, shake, whatever works for you to cause the material to be completely mixed.
Spray it on. I started at one side of the repair, squeezed trigger, moved not to slowly to the other side of the repair, then released trigger. Repeat in the other direction. Slowly build up gel coat with each pass. Be careful to not build up to quickly, runs may occur on vertical surface.
Use the other spray bottle to apply the Form Release. As I understand it, gel coat needs vacuum to cure properly and one way of providing it is with form release.
Let it cure for a week. Wash off form release if there is any left. Begin wet sanding as needed with the high number papers. This part will depend on how good of a sprayer you are and if you used the right amount of hardener and thinner.
Hi, thanks for the responses. I have about 20 of these on the boat, so I have my work cut out for me. I was fortunate to have got off of the lake before the storm hit (it was quite fast moving and there was a lot of smoke from forest fires in the air, making the weather difficult to judge that day). We were lucky also in that the storm caused a tornado (the bad kind) that struck about 15 miles away. Between my folk's vehicles, the cottage roof, my truck and holiday trailor and boat, this is turning into quite an event insurance-wise. Al
If you want to really make it look pretty, and help with the elbow-grease, a Dremmel or similar tool with a grinding bit will remove the cracked gelcoat quickly. If you don't have mold release, a sheet of mylar (found in the gelcoat repair kits) works just as well. I've used waxed paper, but the mylar (when mold release isn't available) works better. I extend the new gelcoat about 1/2" past the repair area, and feather sand it to blend and smooth when it's done.
If you're working on the non-skid area, you can get a similar texture by spraying on the gelcoat and then gently blowing sugar on the surface before applying the mold release. When all is cured, just hose off the surface. The mold release and the sugar will be removed, leaving a non-skid surface. They use this on surfboards a lot ("sugar deck")
Use the other spray bottle to apply the Form Release. As I understand it, gel coat needs vacuum to cure properly and one way of providing it is with form release
There is a better way. I just had my Nacra put back together. The guy that repaired it put a additive into the gel before he sprayed it. From what I understand, it's called "air-wax"
After the gel is sprayed, the wax comes to the surface and blocks the air. Simple, easy, and it works GREAT.
